Strip tension device



Aug. 13, 1935.- F KUCERA STRIP TENSION DEVICE 2 Sheets-Shet 1 Filed April 30, 1934 3, 1935. F. A. KUCERA 2,611,492

STRIP TENSION DEVICE Filed April 30. 1954 2 Sheets-Sheet 2 Patented Aug. 13, 1935 UNITED STATES PATENT]OFFICE);

Frank A. Kucera, Chicago, Ill.,. assignor to Union Special Machine Company, Chicago, Ill., acorporation of Illinois Application. April3 0, 1934, Serial No. 723,242 I .10, Claims.- (o1. 112 152) The present invention relates to new and useful improvements in strip tension devices for sewing machines, and more particularly to an improved tension device for applying tension to a binding 5 strip, and the invention "further relates to the provision of novel means under the control of the operator for applying or releasing the tension atwill.

In the co-pending application of Herbert McK.

Carmichael, et al., Serial No. 636,764; filed October 7, 1932 there is shown 'anddescribed a method of binding the edges of knittedfabric sections'and the tension device shown and described herein is particularly adapted for suchiuse whereinit is desirable to apply tensionto the binding strip when stitching crosswise of 'the'wales and wherein it is'desi'rable to release the'tension on thestrip when stitching lengthwise of the Wales. It is to be clearly understood, howeveijthat the tension device, which is the subject of the present application, may be used withany type of strip where it is desired to apply tension thereto or to release the tension already applied thereto. An object of the invention, therefore, is topro vide a strip tension device which maybe utilized for? the 'above purpose and wherein the tension is released by'cam actuating means under the control of the operator. 1 I

A further object of the invention is to provide a tension device wherein, by a slight adjustment, tension'is normally applied or tension is normally released and wherein, in either caseirneans under the control of theoperator are-provided for releasing the ten'sion'in onecaseand tor applying "the tension in the other case. v

A further object of the invention is to provide a strip tension device for use with sewing 'machineswherein, by a slight adjustment, the tension maybe released by" spring means or by acontrol' member movedby the operator.

"I'he above'and other objects of the invention will in part be obvious and will be" hereinafter morefully disclosed. 4 r a Inthe accompanying drawings:

- Fig. 1 is a view showing the strip tension device applied to. a sewing machine.

'Fig. 2 is a side view of the tension device set for normally applying tension to the bin'ding strip and showing: in dotted lines, the position of the parts when the operator releases the tension.

Fig. 3 is a rear view. of the :device shown in Fig. 4 is a detail sectional'view; of the tension device shownin Fig.2.

Fig. 5. is a rear view of the tension device set for normally releasing the tension from the binding strip.

Fig. 6 is a fragmentary side sectional view of the device shown in Fig. and showingin dotted lines, the position'of the parts when the operator applies tension to the strip. 1 Fig; '7 'is a sectionaljview taken along line l,-1 ofFig;4."- m i The invention as illustrated is shown as .applied to a sewing machine for; binding fabricsec: tions. It is often desirable in the attaching of a strip to a, fabric section to place the strip under tension as it is fed to the stitching mechanism, or to release it in order tobring about a proper placing'or releasing of the strip relative to the'iabric for; stitching. In the application of 'HerbertMoK'. Carmichael, et al., referred to above, a: tension device is shown as applied-to a machine of this type which-isespecially adapted for the stitching tension is controlled by the operator andisxreleasable at will so that the fabric strip may move freely through the binder without .any tension being applied thereto, or the-tension may be applied tothe bindingstrip so as to strain its move The tension device consists of two plates be tween which the fabric strip passes. One of these platestis carried by-a bracket attached to a table while the other is mounted-on the bracket so that it may be moved toward andaway from the first Posts carried bythe bracket ex-. tend through the movable tension device, and springs -mounted on said posts and "bearing named plate.

against the movable tension member normally press said movable member-against the fabric stripto create tension thereon. .At the: ends of the movable member. are pins. which "extend through the bracket; At the rear of the bracket is a bar which ispmounted for'sli'ding movement vertically of. the bracket. .This bar hasrecesses formed in its inner face." There is airecess associated' with each pin, and the pins have rounded ends and extend through the bracket into these recesses.- The recesses at the upper'and' lower ends are graduallyztapered toa flush position with the face of thelbar thus producing cam actu- .ating means; The.. spring moves the bar in one 20 of a knitted binding strip to a knitted fabric. The

the tension plates. treme lower position by the actuation of the treadle then the upper cam becomes effected to sep-, arate the plates. A stop screw is provided which may be' shifted frorn'one set position to another for limiting the movement of the bar. This provides a means whereby the machine may be set so that the operator by depressing the treadle will release. the tension and when the treadle is released the tension will be applied,- or again the spring will lift the bar 'so' as to release the tension and when the operator depresses the treadle the tension will 'be applied.

Referring more in detail to the accompanying drawings, there is shown, in Fig. 1, a sewing machine which includes an overhanging arm l and a needle head in which the needle bar |2,'

carrying the needles l3, reciprocates. The material is held onthe work support M by a. presser footv l5 and is fed across the'said work support ing strip. The edge of the fabric is directed to the stitch forming mechanism by aguide l9 and the binding strip I8 passes through a binder which folds the edges of the 'strip as' it is fed beneath the presser foot. The above mechanism is clearly shown in the co-pending application of Herbert McK. Carmichael et al. above referred to,

and no furtherdescription is considered neces sary here. The binding strip passes through a vtensioning device before entering the-binder 20 and this tension device is mounted on the upstanding arm- 2| of an angular bracket member,

the laterally extending arm 22 of which is secured to the sewing machine table 23. The operator may'readily control the operation of the tension device by a foot treadle 24 which is connected by a cord 25 extending through an opening in the table to'an actuating member 26.

- The particular details of the strip tension device will be more fully described and it is thought thatthe description will be better understood by I referring to Figs. 2Yto 7. 'A tension plate 21 is mounted on the arm 2| of the bracket in fixed parallel relation thereto by the spaced posts 28 plate 29 toward the fixed plate 21 and the tension exerted by the springs on the plate 29 may be adjusted by nuts 3| carried by the outer ends of the posts against which the ends of the springs abut. The plate 29 is longer than the plate 28 and pins 32,33 are carried by the protruding ends thereof. These pins 32 pass through openings in the bracket armr2| and are provided with rounded ends 32a, 33! which extend slightly beyond:the opposite side of the bracket arm.

A shiftable plate 34 is mounted on the opposite 7 side of the bracket arm 2| by means of screws 35 whichextend through longitudinal slots 31" in the plate 34v and which are provided'with stop shoulders 36 which limit the movement thereof into the bracket arm and so permit a free shifting movement of the plate longitudinally but not laterally of the bracket arm 2|. The shiftable plate 34 is provided with a lateral extension 38 to which the cord 25 is connected. A spring 39 having one end thereof connected to the upper end of the bracket arm 2| and having the other end thereof connected to the upper end of the plate 34 normally holds the plate 34 in a raised position.

It will thus be seen that, by depressing the foot treadle 24, the plate will be caused to descend l but, upon release of the treadle, the spring 39 .will return the plate to its normal raised position; At one side of the plate 34 and intermediate the slots 31 is a cut out portion 40 which permits the insertion of a set screw 4| in; either of two-threaded openings 42, 43 in the bracket arm 2|, and this set screw serves as a stop for the plate or bar 34. The inner faceof the plate 34 is provided Withlongitudinal recesses .44, 45

into which the rounded ends of thepins 32, 33

respectively extend as shown in Fig. 4. The upper and lower edges of the recesses are tapered to a position flush with the inner face of the plate 34 so as to provide cam surfaces for ac tuating the pins in-a manner tobe hereinafter fully described. 7 V

, As shown in full lines 'in Figs. 2, 3 and ,4, the set screw 4| is in the lower position,,that is, in

the threaded opening 43, and the rounded ends of the pins 32, 33 do not contact the surface of the'recesses 44, 45 respectively so that the tension plate 29 is urged inwardly intension applying position against the strip 8 which passes between the two tension plates. In thispositlon the treadle is released and the spring 39,,holds the bar 34 in a raisedposition. When the operator depresses the treadle 24, the bar, 34 is moved to the dotted line position, shown in Figs. 2 and 3 and the upper tapered cam surfaces of the recesses 44, 45 contact the rounded ends 32a, 33a, of the pins 32, 33 respectively, and force the pins outwardlywhereby. the. tension plate 23 is shifted away from the strip l8, as shownin-dotted lines in Fig. 2, in order to release the tension on the strip. g

, InFigs. 5 and 6, it will be notedthat the set screw 4| is shown in the upper threaded opening 42 and in thisposition, as shown in .full-linesyin Figs 5 and 6, the tension plate 29 ,isinor'mally heldin tension releasing position away from the strip l8 because the spring 39 holdsithebar 34 in araised position so'thattheends of'the pins are forced outwardly by the-lower cam surfaces of the recesses 44,45, as shown in'Fig." 6. When the operator depresses the treadle 24,'the bar 34 is caused to assume the position,v shown in dotted lines in 'Figi 6, wherein the tension plateand pins 32, 33 are forcedinwardly by the springs 30 and the 'ends of thepins may extend into the recesses 44, 45, so that tensionis applied 'to the-strip. I8.

' From the foregoing description, it will'be seen that the outer or movable tension plate 29 is shifted in a direction at right angles to the .longitudinal'axis of thebracket"arm"2| by means of the bar or plate 34 which is moved in a direction which is parallelto the longitudinal axis of -s 'ets manually.

tension device may be manually set to either {normallyapplytensionto the strip, or to nor-- mally release' the tension from the strip-depending'up'on which of the openings 42, 43, that the setscrew M is placed, but in either-case, the ope ration of the tension plate '29 through the pins 32, 33 is caused by the movement of the bar 34 which is directly controlled by the operator through the treadle'M and connecting cord 25. It will thus be seen that the present invention provides a strip tension device which may be set, in'the first instanca'to normally apply tension to a strip or,'in the second instance, to normally release the tension from the strip and the type of work or desireof the operator will determine in which position the device should be set. In either instance, cam actuating means on a slidable opcrating plate under the control of the operator are provided for releasing the tension orv applying ten sion depending upon which position the device Of course, minor changes in details of construction and arrangement of partsmay be made-with out departing from the-scope of the invention as set forth in-the'appended clainisj @Having thus fully described my invention, what I claimas new and desire to secure by Letters Patcm, is': Y

1} A sewing machine including, in combination, a stitch forming mechanism, a guide for directing a binding stripabout the edgeof the fabric and 'tofithe'stiftch forming mechanism, and a tension device-through which the binding strip passes,

said tension device comprising asupporting bracket, a fixed tension platecarried by, said bracketandacrosswhich the binding strip passes, a tension plate carried by said bracket and movable toward and away fromsaidfixedtensionplate,

spring means for normally forcing said movable 2. A sewing machine including,.in combination, a stitch forming mechanism, a guide for directing abindingstrip about the edge of the fabric and to the stitch forming mechanism, and a tension devicethrough which the strip passes, said tension j devicecomprising a-s'upporting bracket, a fixed f tension plate carried by said bracket, a tension plate movable toward and away from said fixed tension plate, pins carried by said movable tension plate extending through said supporting bracket, spring means for normally forcing said movable tension plate to apply tension to the strip, an actuating plate mounted on the opposite side of said bracket for movement relative thereto, and cam means associated with said plate for'engaging the free ends of said pins for shifting said movable tension plate to release the tension on said strip.

3. A sewing machine including-in combination, a stitch forming mechanism, a guide for directing a binding strip about the edge of the fabric and to the stitch forming mechanism, and a tension device through which said strip passes, said tension device comprising a supporting bracket, a fixed tension plate carried by said bracket and over which the strip passes, a tension plate carried by said bracket and movable toward and away from said fixed tension plate, posts extending through both of said tension plates, springs carried by said posts and bearing against saidmovable tensionplate for normally forcing the same toward said fixed tension plate to apply tension to thestrip', pins'secured to said movable"tension plate and extending entirely through'said bracket, 'an'aetuating'plate secured to the opposite sideof said bracket for limited movement lohgitudinally thereof, cam faced recesses" on the inner 'face* of said actuating plate and adapted to cooperate with the free ends of said pins, and means for shifting said actuating plate whereby to cause f'saidcam .faces to engage the ends of said pinsto' shifts'aid movable tension plate.

4. A sewing machine including, in combination,

a stitch forming mechanism, means for directing a strip thereto, and a tension device through which said strip is adapted to pass, saidten'sion device comprising a supporting member, a fixed tension plate carried by said supporting member, a movable tension plate carried by saidsupporting member, spring means for normally forcing said movable tension plate toward said-fixed tension plate to apply tension to said strip, an operat-- ing bar, means including a pin and Slot connec tion for mounting said bar on said supporting member for movement in a dire'ctiori at -right angles to the direction of movement of said movable tension plate, and means operableflupon the movement of said operating bar for shifting said movable tension plate. i

5.. A sewing machine including, in combination,

a stitch forming mechanism, means fordire'cting a strip thereto, and a tension device through which said strip is adapted topass, said tension device comprising a supporting" member, a fixedtension plate carried by said supporting member, a movable tension plate carried by said supporting m'e'mfber, spring means for normallyforcingsaid mov'- able tension plate toward said fixed tension. plate to apply tension to said strip; an operatingfbar having cam surfaces thereon, means including 'a pin and slot connection for mounting said operat ing bar on said supporting member for movement relative thereto, and means cooperating with the cam surfaces on said operating bar for shifting said movable tension plate away'from-said fixed tension plate to: release the tension on strip. I i 6. A sewing machineincluding, in combination, a stitch forming mechanism, means for directing a strip thereto, and a tension device through which said strip is adapted to pass, said tension device comprising a vertical supporting member having a threaded opening, an operating bar secured to said supporting member for movement relative thereto, said bar having a cut out portion registering with said threaded openings, a stop screw adapted to be inserted in said opening, a fixed tension plate carried by said supporting member, a movable tension plate carried by said supporting member, spring means for normally forcing said movable tension plate toward said fixed tension plate to apply tension to said strip,

cam faced recesses on said operating bar, a spring 7 for normally holding said operating bar in a;

raised position with the edge of said out out portion abutting against said screw, pins secured to said movable tension plate and extending through said supporting member and into said recesses on which said strip is adapted to pass,'said tension device comprising a vertical supporting member having a threaded opening an operating bar secured to said. supporting member for movement in a single plane relative thereto, said bar having a cutout portion registering with said threaded 'opening,a stop screw 'adaptedto be inserted in said opening, a fixed tension plate carried by said supporting member, a movable tension plate -carried bysaid supporting member, spring means for normally forcingsaid movable tension plate toward said fixed tension plate to apply tension to said strip, cam facedrecesses on said operating bar, a spring'for normally holding said operating bar in a'raised position with the edge of said cutout portion abutting against said screw, pins secured to said movable tension plate and extend ing through said supporting member and bearing against said operating bar-when said screw is in said opening with the bar raised to abut against the-screw, and means for lowering said operating bar to permit the freeends of said pins to extend into said recesses whereby said movable tension plate is shifted toward said fixed tension plate to apply tension to said strip. I

- 8. A sewing machine including, in combination, astitch forming mechanism, means for directing a strip'thereto, and, a-tension device through which said strip is adapted to pass, said tension device comprising a supportingbracket, afixed tension plate carried "thereby and across which said strip passes, a movable tension plate carried by said bracket and'associated with said fixed tension plate, springs'for forcing said movable tension plate toward said fixed tension'plate for applying tension to said strip, a control bar shii table on said bracket and having spaced cam actuating devices, a device connected to said movable tension plate andwith which one ofsaid cam actuating devices may contact to release the tension on thestrip, a spring for moving said control bar in one direction, and a stop for limiting the movement of said bar, said stop being movable to different set positions whereby one or the other of'said cam actuating devices is rendered effective for releasing the tension on the strip.

9. A sewing machine including, in combination,

a stitch forming mechanism, means for directing a strip thereto, and a tension device through which said strip is adapted-to-pasa-saicl tension device comprising a supporting *bracket, a fixed tension plate carried by'saidbracket'andassw ciated with said fixed tension plate, springs for 1 forcing said movable tension plate toward said fixed tension plate" for applying tensionto said strip, a control bar shiftable on said bracket and having spaced cam actuating devices, adevice connected to'said movable tension plate and with which one of said cam actuating devices may contact to'release the tension on the strip, a spring .for moving, said control bar in one direction, and

a stoplfor limiting the movement ofsaid bar, said stop being movable to different set positions whereby one or the other of said cam actuating devices is rendered effective for releasing the ten;-

sion on the strip, and said cam actuating-devices position, the spring for moving said control bar becomes efiective for releasing the tension onthe strip and when said stop is in the other set position said spring becomes efiective for permitting thetension to be applied to said strip.

10. A sewing machine including,yin combination, a stitch forming mechanism,;meansf,or .di-"

recting a strip thereto, and a tension, device through which said strip is adapted to pass, said tension-device comprising a vertically arranged supporting bracket, .2. fixed tension plate carried by said bracket and movable toward and away from said fixed tension plate in a horizontal direction, an operating barsecuredto the opposite side applying positionor in'a' positionuwherein said movabletension plate isnormally in. tension releasing *position, cam means operable upon the downward -movement of said operating bar f or being so disposed that when said' stopis in one set shifting said movable tension plate away from said fixed tension plate when normally intension applying position, and, spring means operable upon the downward movement; of said operating bar for shifting said movable tension platetoward said fixed tension plate when in normally tension releasing position. I

' FRANK A. KUCERA. 

